Hybrid electric vehicles (“HEV”) are known to include two power sources to drive the vehicle. It is known to use an electric motor in combination with a combustion engine. In a so-called parallel hybrid system, the two power sources either operate individually or simultaneously. Therefore, there is a need for a mechanism to be positioned between the two power sources to allow for either or both power sources to drive the vehicle.
Further, when the vehicle is idling there are competing requirements. The first is to provide minimum power output from the engine to reduce fuel consumption and emissions from the vehicle. On the other hand, the second is to provide enough power for desired vehicle accessories. For instance, the heater, rear defroster and radio may all be on while the vehicle is idling.